STP1419

    Rolling Contact Fatigue Under Water-Infiltrated Lubrication

    Published: Jan 2002


      Format Pages Price  
    PDF (660K) 18 $25   ADD TO CART
    Complete Source PDF (13M) 18 $143   ADD TO CART


    Abstract

    This paper describes bearing life under water-infiltrated lubrication, which is often much shorter than the calculated bearing life. Bearings that failed in the field under water-infiltrated lubrication were analyzed to identify the mechanism. However, this was difficult due to insufficient information of the failure process. New fatigue life test methods were then developed to reproduce short life under water-infiltrated lubrication, to precisely observe the flaking process, and to study what material parameters affect the bearing life. It was found that failure under water-infiltrated lubrication initiates from nonmetallic inclusions on the rolling contact surface and propagates initially following grain boundary and then cutting through the grain, which eventually results in flaking. Higher cleanliness, which means less failure initiations, and nickel (Ni), which strengthens grain boundaries, improves bearing life under water-infiltrated lubrication. Hydrogen-induced failure is also experimentally studied to further understand water-induced failure. Hydrogen-induced failure is different from water-induced failure in the mechanism.

    Keywords:

    Bearing, rolling contact fatigue life, water-infiltrated lubrication, boundary lubrication, flaking, peeling, elastohydrodynamic film parameter (lambda), hydrogen embrittlement, delayed fracture


    Author Information:

    Matsumoto, Y
    Manager, executive chief engineer, and general manager, NSK Ltd., Kanagawa-ken,

    Murakami, Y
    Manager, executive chief engineer, and general manager, NSK Ltd., Kanagawa-ken,

    Oohori, M
    Manager, executive chief engineer, and general manager, NSK Ltd., Kanagawa-ken,


    Paper ID: STP10857S

    Committee/Subcommittee: A01.28

    DOI: 10.1520/STP10857S


    CrossRef ASTM International is a member of CrossRef.